1. Field of the Invention
The present invention relates to lighting, more particularly, to a lamp that can be fixed to a position and electrically connect to a power supply to illuminate.
2. Description of the Related Art
Referring to FIG. 1, a conventional lamp 9 includes a first shell 91 having a plurality of inlets 911 and a base 912, a second shell 92 having a plurality of outlets 921 and a lens 922, a heat dissipating unit 93 and a light emitting member 94. The inlets 911 are annularly arranged on a wall of the first shell 91 and around the base 912, with a rib 913 being between any adjacent two inlets 911. And the outlets 921 are annularly arranged on a wall of the second shell 92 and around the lens 922, with a rib 923 being between any adjacent two outlets 921. Besides, the first shell 91 and the second shell 92 are combined to jointly form a hollow housing. The heat dissipating unit 93 and the light emitting member 94 coupled to each other are fixed inside the hollow housing, with a light emitter of the light emitting member 94 facing the lens 922.
In use, the lamp 9 is generally coupled to a lamp holder (not illustrated) set on a wall, ceiling or table, so as to electrically connect to a power supply through the base 912 for the light emitting member 94 to emit light penetrating the lens 922 for illuminating. Furthermore, heat generated by the light emitting member 94 can be transmitted to the heat dissipating unit 93 and then be further transmitted to outer space of the hollow housing through the outlets 921 by air flows induced by the heat dissipating unit 93 through the inlets 911. Therefore, life of the light emitting member 94 is extended.
In general, for safety, sizes of the inlets 911 of the first shell 91 and the outlets 921 of the second shell 92 are limited to prevent fingers of a user from getting into the conventional lamp 9 through the inlets 911 or the outlets 921. For example, in UL Standards for Safety, diameters of the inlets 911 of the first shell 91 and the outlets 921 of the second shell 92 are restricted not more than 2 mm. However, during the heat dissipating unit 93 generating the air flows, limitations of size of the inlets 911 and the outlets 921 and gas flow impedance caused by each rib 913 between the inlets 911 of the first shell 91 result in reduction of amount of air inputs. Hence, heat dissipating efficiency of the heat dissipating unit 93 is low. Moreover, while the heat dissipating unit 93 guides the air flows to the outer space, each rib 923 between the outlets 921 of the second shell 92 also causes gas flow impedance, so that the air flows with heat from the light emitting member 94 can't flow smoothly to outer spaces of the housing through the outlets 921. Hence, heat dissipating efficiency of the heat dissipating unit 93 is further lowered. As above description, the conventional lamp 9 has lowered heat dissipating efficiency and life of the light emitting member 94 is not extended effectively. Besides, insects can get into the lamp 9 through the inlets 911 and the outlets 921 of the lamp 9.